Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Nat Commun. 2017 Aug 28;8(1):364. doi: 10.1038/s41467-017-00375-0.
The control of mass transport using porous fibers is ubiquitous, with applications ranging from filtration to catalysis. Yet, to date, porous fibers have been made of single materials in simple geometries, with limited function. Here we report the fabrication and characterization of thermally drawn multimaterial fibers encompassing internal porous domains alongside non-porous insulating and conductive materials, in highly controlled device geometries. Our approach utilizes phase separation of a polymer solution during the preform-to-fiber drawing process, generating porosity as the fiber is drawn. Engineering the preform structure grants control over the geometry and materials architecture of the final porous fibers. Electrical conductivity of the selectrolyte-filled porous domains is substantiated through ionic conductivity measurements using electrodes thermally drawn in the cross-section. Pore size tunability between 500 nm-10 µm is established by regulating the phase separation kinetics. We further demonstrate capillary breakup of cylindrical porous structures porous microspheres within the fiber core.Porous polymer fibers show great potential for a range of applications, but their simple structures typically limit their functionality. Here, the authors combine a thermal drawing process with polymer solution phase separation to fabricate porous multimaterial fibers with complex internal architectures.
使用多孔纤维控制物质传输无处不在，其应用范围从过滤到催化。然而，迄今为止，多孔纤维由单一材料以简单的几何形状制成，功能有限。在这里，我们报告了热拉伸多材料纤维的制造和特性，这些纤维包含内部多孔区域以及非多孔绝缘和导电材料，具有高度可控的器件几何形状。我们的方法利用预成型体到纤维拉伸过程中的聚合物溶液的相分离，在纤维被拉伸时产生孔隙率。通过对预制件结构进行工程设计，可以控制最终多孔纤维的几何形状和材料结构。通过在横截面上热拉伸电极对填充有电解质的多孔区域的电导率进行离子电导率测量来证实其电导率。通过调节相分离动力学，可实现 500nm-10μm 之间的孔径可调性。我们进一步证明了在纤维芯内的圆柱形多孔结构多孔微球的毛细断裂。多孔聚合物纤维具有广泛应用的巨大潜力，但它们的简单结构通常限制了其功能。在这里，作者将热拉伸工艺与聚合物溶液相分离相结合，制造出具有复杂内部结构的多孔多材料纤维。
